I believe you'll be pleased with the flexible panels. I installed 5-120 watt panels purchased from Discount Solar about 2 years ago and have been very pleased with their performance. In my case, I installed a MidNite Solar MPPT controller, two Lifeline GPL-6CT AGM 6 volt batteries (300 amp hr.) and a 1000 watt sine wave inverter.
I know flexible panels have received some bad press, but mine are holding up well so far (fingers still crossed).
I like that you're using lithium batteries and in 10 years when my Lifelines go bad I'm sure I'll upgrade to lithium!